diff options
Diffstat (limited to 'drivers/hwmon/pmbus/max16601.c')
| -rw-r--r-- | drivers/hwmon/pmbus/max16601.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/max16601.c b/drivers/hwmon/pmbus/max16601.c new file mode 100644 index 000000000000..51cdfaf9023c --- /dev/null +++ b/drivers/hwmon/pmbus/max16601.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hardware monitoring driver for Maxim MAX16601 + * + * Implementation notes: + * + * Ths chip supports two rails, VCORE and VSA. Telemetry information for the + * two rails is reported in two subsequent I2C addresses. The driver + * instantiates a dummy I2C client at the second I2C address to report + * information for the VSA rail in a single instance of the driver. + * Telemetry for the VSA rail is reported to the PMBus core in PMBus page 2. + * + * The chip reports input current using two separate methods. The input current + * reported with the standard READ_IIN command is derived from the output + * current. The first method is reported to the PMBus core with PMBus page 0, + * the second method is reported with PMBus page 1. + * + * The chip supports reading per-phase temperatures and per-phase input/output + * currents for VCORE. Telemetry is reported in vendor specific registers. + * The driver translates the vendor specific register values to PMBus standard + * register values and reports per-phase information in PMBus page 0. + * + * Copyright 2019, 2020 Google LLC. + */ + +#include <linux/bits.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "pmbus.h" + +#define REG_SETPT_DVID 0xd1 +#define DAC_10MV_MODE BIT(4) +#define REG_IOUT_AVG_PK 0xee +#define REG_IIN_SENSOR 0xf1 +#define REG_TOTAL_INPUT_POWER 0xf2 +#define REG_PHASE_ID 0xf3 +#define CORE_RAIL_INDICATOR BIT(7) +#define REG_PHASE_REPORTING 0xf4 + +struct max16601_data { + struct pmbus_driver_info info; + struct i2c_client *vsa; + int iout_avg_pkg; +}; + +#define to_max16601_data(x) container_of(x, struct max16601_data, info) + +static int max16601_read_byte(struct i2c_client *client, int page, int reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct max16601_data *data = to_max16601_data(info); + + if (page > 0) { + if (page == 2) /* VSA */ + return i2c_smbus_read_byte_data(data->vsa, reg); + return -EOPNOTSUPP; + } + return -ENODATA; +} + +static int max16601_read_word(struct i2c_client *client, int page, int phase, + int reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct max16601_data *data = to_max16601_data(info); + u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; + int ret; + + switch (page) { + case 0: /* VCORE */ + if (phase == 0xff) + return -ENODATA; + switch (reg) { + case PMBUS_READ_IIN: + case PMBUS_READ_IOUT: + case PMBUS_READ_TEMPERATURE_1: + ret = i2c_smbus_write_byte_data(client, REG_PHASE_ID, + phase); + if (ret) + return ret; + ret = i2c_smbus_read_block_data(client, + REG_PHASE_REPORTING, + buf); + if (ret < 0) + return ret; + if (ret < 6) + return -EIO; + switch (reg) { + case PMBUS_READ_TEMPERATURE_1: + return buf[1] << 8 | buf[0]; + case PMBUS_READ_IOUT: + return buf[3] << 8 | buf[2]; + case PMBUS_READ_IIN: + return buf[5] << 8 | buf[4]; + default: + break; + } + } + return -EOPNOTSUPP; + case 1: /* VCORE, read IIN/PIN from sensor element */ + switch (reg) { + case PMBUS_READ_IIN: + return i2c_smbus_read_word_data(client, REG_IIN_SENSOR); + case PMBUS_READ_PIN: + return i2c_smbus_read_word_data(client, + REG_TOTAL_INPUT_POWER); + default: + break; + } + return -EOPNOTSUPP; + case 2: /* VSA */ + switch (reg) { + case PMBUS_VIRT_READ_IOUT_MAX: + ret = i2c_smbus_read_word_data(data->vsa, + REG_IOUT_AVG_PK); + if (ret < 0) + return ret; + if (sign_extend32(ret, 10) > + sign_extend32(data->iout_avg_pkg, 10)) + data->iout_avg_pkg = ret; + return data->iout_avg_pkg; + case PMBUS_VIRT_RESET_IOUT_HISTORY: + return 0; + case PMBUS_IOUT_OC_FAULT_LIMIT: + case PMBUS_IOUT_OC_WARN_LIMIT: + case PMBUS_OT_FAULT_LIMIT: + case PMBUS_OT_WARN_LIMIT: + case PMBUS_READ_IIN: + case PMBUS_READ_IOUT: + case PMBUS_READ_TEMPERATURE_1: + case PMBUS_STATUS_WORD: + return i2c_smbus_read_word_data(data->vsa, reg); + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static int max16601_write_byte(struct i2c_client *client, int page, u8 reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct max16601_data *data = to_max16601_data(info); + + if (page == 2) { + if (reg == PMBUS_CLEAR_FAULTS) + return i2c_smbus_write_byte(data->vsa, reg); + return -EOPNOTSUPP; + } + return -ENODATA; +} + +static int max16601_write_word(struct i2c_client *client, int page, int reg, + u16 value) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct max16601_data *data = to_max16601_data(info); + + switch (page) { + case 0: /* VCORE */ + return -ENODATA; + case 1: /* VCORE IIN/PIN from sensor element */ + default: + return -EOPNOTSUPP; + case 2: /* VSA */ + switch (reg) { + case PMBUS_VIRT_RESET_IOUT_HISTORY: + data->iout_avg_pkg = 0xfc00; + return 0; + case PMBUS_IOUT_OC_FAULT_LIMIT: + case PMBUS_IOUT_OC_WARN_LIMIT: + case PMBUS_OT_FAULT_LIMIT: + case PMBUS_OT_WARN_LIMIT: + return i2c_smbus_write_word_data(data->vsa, reg, value); + default: + return -EOPNOTSUPP; + } + } +} + +static int max16601_identify(struct i2c_client *client, + struct pmbus_driver_info *info) +{ + int reg; + + reg = i2c_smbus_read_byte_data(client, REG_SETPT_DVID); + if (reg < 0) + return reg; + if (reg & DAC_10MV_MODE) + info->vrm_version[0] = vr13; + else + info->vrm_version[0] = vr12; + + return 0; +} + +static struct pmbus_driver_info max16601_info = { + .pages = 3, + .format[PSC_VOLTAGE_IN] = linear, + .format[PSC_VOLTAGE_OUT] = vid, + .format[PSC_CURRENT_IN] = linear, + .format[PSC_CURRENT_OUT] = linear, + .format[PSC_TEMPERATURE] = linear, + .format[PSC_POWER] = linear, + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | + PMBUS_HAVE_STATUS_INPUT | + PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | + PMBUS_HAVE_POUT | PMBUS_PAGE_VIRTUAL | PMBUS_PHASE_VIRTUAL, + .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_PAGE_VIRTUAL, + .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_PAGE_VIRTUAL, + .phases[0] = 8, + .pfunc[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, + .pfunc[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, + .pfunc[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, + .pfunc[3] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, + .pfunc[4] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, + .pfunc[5] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, + .pfunc[6] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, + .pfunc[7] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, + .identify = max16601_identify, + .read_byte_data = max16601_read_byte, + .read_word_data = max16601_read_word, + .write_byte = max16601_write_byte, + .write_word_data = max16601_write_word, +}; + +static void max16601_remove(void *_data) +{ + struct max16601_data *data = _data; + + i2c_unregister_device(data->vsa); +} + +static int max16601_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; + struct max16601_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA | + I2C_FUNC_SMBUS_READ_BLOCK_DATA)) + return -ENODEV; + + ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf); + if (ret < 0) + return -ENODEV; + + /* PMBUS_IC_DEVICE_ID is expected to return "MAX16601y.xx" */ + if (ret < 11 || strncmp(buf, "MAX16601", 8)) { + buf[ret] = '\0'; + dev_err(dev, "Unsupported chip '%s'\n", buf); + return -ENODEV; + } + + ret = i2c_smbus_read_byte_data(client, REG_PHASE_ID); + if (ret < 0) + return ret; + if (!(ret & CORE_RAIL_INDICATOR)) { + dev_err(dev, + "Driver must be instantiated on CORE rail I2C address\n"); + return -ENODEV; + } + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->iout_avg_pkg = 0xfc00; + data->vsa = i2c_new_dummy_device(client->adapter, client->addr + 1); + if (IS_ERR(data->vsa)) { + dev_err(dev, "Failed to register VSA client\n"); + return PTR_ERR(data->vsa); + } + ret = devm_add_action_or_reset(dev, max16601_remove, data); + if (ret) + return ret; + + data->info = max16601_info; + + return pmbus_do_probe(client, id, &data->info); +} + +static const struct i2c_device_id max16601_id[] = { + {"max16601", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, max16601_id); + +static struct i2c_driver max16601_driver = { + .driver = { + .name = "max16601", + }, + .probe = max16601_probe, + .remove = pmbus_do_remove, + .id_table = max16601_id, +}; + +module_i2c_driver(max16601_driver); + +MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); +MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601"); +MODULE_LICENSE("GPL v2"); |